32+ Collateral Conjoint Vascular Bundle PNG. The xylem and phloem are in the same line, cambium is absent, phloem is external to xylem, protoxylem faces the centre. The central vascular bundles of monocot stem are large sized.
Therefore, the vascular bundle is called collateral closed. When xylem and phloem of a vascular bundle lie on the same radius, it is called the conjoint vascular bundle. Xylem towards inner side & phloem.
Sructurally roots have radial primary vascular bundles and stem has conjoint and collateral vascular bundles.
Here the xylem and phloem are arranged together in the same radius. The peripheral region of cells in the stem is called the cortex; Cells of the central portion make up the pith. Organization of the vascular tissue: